Answer:
116.82 square inches
Explanation:
The overall shape is that of a 10-inch square with four triangles attached. Each of those is an isosceles right triangle with leg lengths of 2.9 inches.
The area of the four triangles is ...
total triangle area = 4(1/2)(2.9 in)(2.9 in) = 16.82 in²
The area of the 10-inch square is ...
square area = (10 in)² = 100 in²
Then the total window area is ...
window area = 16.82 in² +100 in²
window area = 116.82 in²